142 Canadian Record of Science. 
These graptolite-bearing rocks are clearly of about 
Middle Ordovician age. They contain forms I would refer 
to the second or Black River Trenton period: i.e. they are 
newer than the Point Lévis series, and older than the Hud- 
son and Utica groups. The association of forms is such as 
we find in Britain and Western Europe, in the passage beds 
between the Llandeilo and Caradoc Limestones. The rocks 
in Canada and New York, with which these Dease River 
beds may be best compared, are the Marsouin beds of the 
St. Lawrence Valley, and the Norman’s Kill beds of New 
York. The Dease River beds may perhaps be a little older 
than these. 
Mr. C. White described some Graptolites from beds in 
the mountain region of the West, several years ago, which 
may belong to the same horizon as the Dease River zones, 
though they have a somewhat more recent aspect. 
The specific identification of the Dease River fossils, I 
regard as provisional. While the species correspond 
broadly with those found in their eastern equivalents, they 
have certain peculiarities which may, after further study, or 
on the discovery of better and more perfect specimens, lead 
to their separation as distinct species or varieties. 
It is exceedingly interesting to find Graptolites in a 
region so far removed from the Atlantic basin, and also to 
note that the typical association of Llandeilo—Bala genera 
and species is still retained practically unmodified. 
THE GREAT LAKE Basins oF CANADA. 
: By A. T. Drummonp. 
In a paper read recently before the Royal Society of 
Canada, on “‘ The Origin of Some Geographical Features in 
Canada,” Dr. Bell alluded more particularly to the lake 
region of the Dominion, including in this not only what is 
Notr.—This preliminary note comprises a short extract from the 
closing lecture in Science, delivered by the author before the autho- 
rities of Queen’s University on April 23rd of this year, and its pub- 
lication has been suggested by Dr. Bell’s more recent paper, above 
alluded to, read before the Royal Society. 
